/Engine/Plugins/FX/Niagara/Source/NiagaraEditor/Public/ViewModels/NiagaraEmitterViewModel.h
Add an event script to the owned emitter. Sets the Usage, UsageID and Source of the EventScriptProperties.
void AddEventHandler ( [FNiagaraEventScriptProperties](API\Plugins\Niagara\FNiagaraEventScriptProperties) & EventScriptProperties, bool bResetGraphForOutput )